Hurricane Joaquin strengthened once again early Thursday, packing 120 mph winds as a second storm threatened historic rainfall and potential flooding for the Carolinas and Virginia this weekend.

The Category 3 hurricane powered toward the Bahamas and was about 75 miles southeast of San Salvador Island at 8 a.m. ET, moving at about 5 mph.

Different forecast models predict Joaquin will either veer northwestward, ramming into Virginia, Maryland or North Carolina this weekend, or avoid the East Coast entirely as it takes a more easterly track up the Atlantic. Overnight, the American model trended towards the European model in predicting that the storm would not make landfall in the U.S.

Regardless of Joaquin's path, the Carolinas and Virginia appeared in line to be soaked by a separate storm pulling tropical air into the region. Between 10 and 15 inches of rain has been forecast over a 72-hour period from Friday through Sunday — with as much as 20 inches in some places. Parts of Maryland, Delaware and New Jersey are also expected to be drenched this weekend.

Heavy rain was already falling late Wednesday, and at least one person died in flash floods in Spartanburg, officials said.

Virginia Gov. Terry McAuliffe on Wednesday declared a state of emergency, and North Carolina Gov. Pat McCrory ordered state agencies to prepare for floods.

"I cannot stress enough the imperative for Virginians to focus on the rainstorms that are headed our way [Thursday] and Friday, well before Hurricane Joaquin could potentially impact Virginia," McAuliffe said. "The forecast of up to 10 inches of rain in areas across Virginia could result in floods, power outages and a serious threat to life and property."

In Kitty Hawk, North Carolina, officials were hoping sandbags protect the town if the hurricane strikes the Outer Banks. "It could be some resemblance of what Sandy offered us, and we've learned some lessons from that," Kitty Hawk Mayor Gary Perry told NBC station WAVY.

In New York, Gov. Andrew Cuomo said: "Our state has seen the damage that extreme weather can cause time and time again — and I am urging New Yorkers to take precautions for more heavy storms in the coming days."

Disney Cruise Line rerouted a ship headed toward Nassau in anticipation of the hurricane, and said the vessel would go to Key West instead. Another Disney ship out of Port Canaveral will have its itinerary rerouted. Carnival Cruise Lines also modified the routes of two cruises, the company said.

Authorities in the Bahamas fear storm surges, coastal flooding and up to 10 to 15 inches of rain, said Geoffrey Greene, a senior forecaster with the Bahamas Meteorology Department.

"We would be very concerned about them," Greene said of the eastern islands.